First off, I’d like to define lifting weights in the terms which I am referring to:

A woman who lifts weights or takes part in resistance training 4-5 days per week, with balanced body-part exercises during a week. I am not referring to crossfit…

Most of these reasons fall under simple genetic differences between men and women.

Reason 1: You don’t have enough testosterone or growth hormone {the main two hormones that promote muscle growth}.